Spring construction



June 18, 1968 L. H. CROSBY ET AL SPRING CONSTRUCTION Filed Nov. 28, 1966 V5670! Irv/Mir 2 Sheets-Sheet 1 44/1/70 6f CPU-58y EUGENE 5 FE'l/VGOLD 174mg I June 18, 1968 CROSBY ET AL 3,388,904

SPRING CONSTRUCT ION 2 Sheets-Sheet 2 Filed NOV. 28, 1966 United States Patent 3,388,904 SPRING ONSTRUCTION Lawton H. Crosby, 403 Center Ave., Lake Bluff, Ill.

60044, and Eugene B. Feiugold, 3500 N. Lake Shore 5 Drive, Chicago, II]. 60613 Continuation-impart of applications Ser. No. 301,552, Aug. 12, 1963, and Ser. No. 434,563, Feb. 23, 1965. This application Nov. 28, 1966, Ser. No. 602,448

8 Claims. (Cl. 267-111) ABSTRACT OF THE DISCLOSURE This is a continuation-in-part application of our copending applications Ser. No. 301,552, filed Aug. 12, 1963, and Ser. No. 434,563, filed Feb. 23, 1965, both now abandoned.

This invention relates in general to furniture and other seating arrangements, and more particularly to a seating arrangement employing springs of the sinuous spring band type.

It is an object of the present invention to provide a greatly improved spring assembly for a seating arrangement.

It is another object to provide a new and improved sinuous spring band construction which introduces luxurious resilience to a seating arrangement heretofore found only in more expensive spring constructions such as tied coil springs and the like.

It is still another object to provide a sinuous spring band construction which eliminates bucketing (contourarc reversal) of the center portion of the band.

It is yet another object to provide a sinuous spring band construction which eliminates jack-knifing (contour-arc reversal) of the rear portion of the band immediately adjacent the rear frame rail.

It is a further object to provide a sinuous spring band construction which produces deep-drop support of the subject seated on the furniture seat, for example.

It is still a further object to provide a sinuous spring band construction which assures substantial assisting uplift to the seated subject when rising from the seat.

It is yet a further object to provide a sinuous spring band construction which provides much more effectively resilient support to the seated subject than heretofore considered possible without accompanying hardness, and permits adjustable control of resilience.

It is still a further object to provide a sinuous spring band construction which inherently develops a highly desirable seat contour to eliminate the cushion gap found in other sinuous spring assemblies.

It is yet another object to provide sinuous spring band construction which facilitates the establishment of a wide 3,388,904 Patented June 18, 1968 ice range of choices from firmness to softness in seating arrangements.

It is still another object to provide a sinuous spring band construction which is readily used in frames of varying size, without modification.

It is another object to provide a sinuous spring band construction which has all the aforementioned advantages forthcoming whether used in standard and long span frames or ultra-short frames.

The foregoing and other objects are realized in accord With the present invention by providing a sinuous spring band assembly which permits a full-range of seating effects to be achieved using basically the same or similar spring bands. In one aspect of the invention, downwardly bent portions of the band are formed adjacent both the front and back rails of a furniture frame or the like, with the free ends of the band connected to corresponding rails. As a result, downward pressure applied to the band by a subject being seated, for example, effects travel of the downwardly bent portions relative to their rail mountings and stored resilience is developed in the body of the band. Deep-drop support of the seated subject is assured and bucketing at the center of the band and jack-knifing adjacent the rear rail are eliminated.

In another aspect of the invention, specifically advantageous effects are achieved by the development of differential stored resilience in the band at the front and rear rails. The downwardly bent portion of the band adjacent the rear rail is bent at a greater angle to the remainder of the band than the correspondingly downward bent portion adjacent the front rail. As a result, the spring band assumes a greater torque at the rear rail and highly desirable rearwardly inclined contour is developed. Furthermore, relatively greater stored resilience is developed in the spring band adjacent the rear rail, where the bulk of the weight of a seated subject is carried when the subject is seated.

In yet another aspect of the present invention, subtle but significant variations in the differential stored resilience developed in the spring band by the downwardly bent portions of the band when a subject is seated are selectively introduced through the use of generally horizontal, outwardly extending band portions or separate members connecting the downwardly bent portions to either the front rail or the back rail, or to both rails. These generally horizontally extending band portions or separate members act as translatory support members to vary the compression by introducing stored resilience in a less pronounced manner through translation and vector thrust rather than straight pivoting of the downwardly bent portions about their rail connections when a subject is seated.

In still another aspect of the invention, a horizontally extending band portion or separate member is employed to develop vector thrust and translation adjacent the back rail only. The translation once more induces stored resilience in a less pronounced manner than a direct pivotal connection, for example, to produce a softer seat.

The invention, both as to its construction and method of operation, is illustrated more or less diagrammatically in the attached drawings, in which:

FIGURE 1 is a side elevational view of a furniture spring arrangement incorporating a sinuous spring band assembly embodying features of a first form of the present invention, with parts removed;

FIGURE 2 is a side elevational view of the relaxed sinuous spring band employed in the first form of spring band assembly illustrated in FIGURE 1;

FIGURE 3 is a diagrammatic side elevational view of a furniture spring arrangement incorporating a sinuous spring band assembly embodying features of a second form of the present invention;

FIGURE 4 is a diagrammatic side elevational view of a relaxed sinuous spring band employed in the spring band assembly illustrated in FIGURE 3;

FIGURE 5 is a diagrammatic side elevational view of a furniture spring arrangement incorporating a sinuous spring band assembly embodying features of a third form of the present invention;

FIGURE 6 is a diagrammatic side elevational view of a relaxed sinuous spring band employed in the spring arrangement illustrated in FIGURE 5;

FIGURE 7 is a diagrammatic side elevational view of a furniture spring arrangement incorporating a sinuous spring band assembly embodying features of a fourth form of the present invention;

FIGURE 8 is a diagrammatic side elevational view of a relaxed sinuous spring band employed in the spring arrangement illustrated in FIGURE 7; and

FIGURE 9 is an enlarged plan view of a portion of the spring arrangement illustrated in FIGURE 1;

FIGURE 10 is an enlarged plan view of another form of back-rail connection for the spring assembly;

FIGURE 11 is an enlarged elevational view of still another form of back-rail connection;

FIGURE 12 is an enlarged plan view of yet another form of back-rail connection;

FIGURE 13 is an enlarged elevational view of a further variation of the back-rail connection;

FIGURE 14 is an enlarged elevational view of a modified variation of the back-rail connection; and

FIGURE 15 is a side elevational view, with parts broken away, of a simplified spring arrangement embodying features of the present invention.

Referring now to the drawings, and particularly to FIGURES 1 and 9, a furniture spring arrangement of the sinuous spring band type is illustrated generally at 10. The spring arrangement 10 includes a sinuous spring band assembly 11 embodying features of a first form of the present invention mounted between the front rail 12 and the back rail 13 of a conventional furniture frame 14 (only part of which is shown) for a chair, sofa, or vehicle or the like. Only one spring band assembly 11 is illustrated, but as will be readily understood, the frame 14 normally mounts a parallel series of these assemblies 11.

Each of the spring band assemblies 11 includes a new and improved sinuous spring band connected to the front rail 12 by EK clip 21 and to the back rail 13 by EK clip 22, for pivotal movement about their connections. The spring band 20 inherently develops center area stored resilience in the band 20 as a subject is seated to assure deep-drop support of the subject, the avoidance of center area bucketing in the band, and the avoidance of rear-area jack-knifing or the like. The new and improved spring band 20 develops a highly attractive and effective contour with a slight rearward incline and provides what is characterized relatively as a firm" seat in any type of frame, regardless of its length.

In contrast to the sinuous spring band assembly 11, the spring band assembly 111 illustrated in FIGURE 3 and embodying features of a second form of the present invention develops a slightly softer seat; one which might be termed medium firm in the relative scale. This variation in firmness is achieved by providing a lesser rate of increase in stored resilience in the spring band 120 adjacent the front rail as the subject is seated.

A third form of sinuous spring band assembly embodying features of the present invention is illustrated at 211 in FIGURE 5. The sinuous spring band assembly 211 provides a still softer ,seat on the relative scale, and might be termed medium soft, by providing a lesser rate of increase in stored resilience in the spring band 220 adjacent the back rail 13 as a subject is seated.

Turning to FIGURE 7, a fourth form of spring band assembly embodying features of the present invention is illustrated generally at 311. The spring band assembly 311 produces the softest of seats on the relative scale and is generally referred to as soft. In other words, even in the shortest of frames such as might be employed in private aircraft, recliners, and so on, for example, where other torque sinuous constructions cannot function properly, superior resilience and greater comfort in a sinuous spring band seating arrangement is afforded. In the spring band assembly 311, increase in the rate of stored resilience in the band 320 is lessened adjacent both rails 12 and 13.

Referring once more to FIGURES 1 and 9, in the sinuous spring band assembly 11 embodying features of the first form of the present invention, the sinuous spring band 20 illustrated is a regular loop sinuous spring band. In other words, its individual loops 23 are broadly of standard configuration and dimension. The linear segments 25 and interconnecting semi-circular segments 26 which define each loop 23 are of a predetermined standard length and radius, respectively. Although the spring band 20, embodying features of the first form of the present invention, is illustrated as a regular loop spring band, however, it should be understood that expanded loop (XL) and superloop spring bands (other forms well known in the furniture business) might also be used.

Precedent to describing the spring band 20 in its assembly 11, a better understanding of the invention is facilitated by referring to FIGURE 2 and the illustration of the band in relaxed relationship. The band 20 will be seen to describe the larger part of a complete circle. A rear end section 28 of the relaxed band 20 is bent inwardly of the circle at an angle of approximately 80-90 thereto, and a front end section 29 is bent inwardly of the circle at a lesser angle of approximately 7080. Varying these angles in proportion, however, can be done to control resilience. The rear end section 28 includes the last linear segment 30 in the band 20 and the last semi-circular segment 31 thereof, bent inwardly about the second last linear segment 32. Correspondingly, the front end section 29 includes the last linear segment 34 at the opposite end of the band, and the last semi-circular segment 35 thereof, bent inwardly about the second last linear segment 36.

Returning now to the spring assembly 11 as illustrated in FIGURES 1 and 9, the sinuous spring band 20 is connected to the front rail 12 by the EK clip 21 and the back rail 13 by the EK clip 22, as has been pointed out. In this light, the last linear segment 30 of the rear end section 28 is held in the loop of the EK clip 22 while the last linear segment 34 of the front section 29 in the band 20 is retained in the loop 41 of the EK clip 21. It will thus be seen that each end of the band 20 is mounted for pivotal movement about corresponding end linear segments 30 and 34 held in EK clip loops 4t] and 41, respectively.

It will be noted also that a free end 34a of the last linear segment 34 in the front end section 29 is bent in an are generally perpendicular to the plane defined by the linear segment 34 and 36 and the semi-circular segment 35. As such, the linear segment 34 cannot pull out of the EK clip loops 41 during flexing of the band 20.

When the spring band 20 is stretched between the front rail 12 and the back rail 13 in the foregoing manner, it will be recognized that a downward torque or moment arm is introduced in the band adjacent the back rail 13 by the downwardly bent end section 28 of the band. At the same time, the downwardly bent attitude of the front end section 29 of the band 20 introduces a corresponding downward torque or moment arm in the band adjacent the front rail 12. These opposing torques develop latent compression in the central body portion 45 of the band 20.

As a subject lowers into seated relationship on the spring band assemblies 11 making up the spring arrangement 10, the opposite end sections 28 and 29 of the band pivot about their mounting linear segments and 34, respectively, and compression in the spring band is progressively increased. As a result, the strength of the spring assembly 11 is progressively actually increased and bucketing of the band in the central body portion (such as was frequently encountered with known sinuous spring band arrangements) is avoided. At the same time, the stored resilience developed in the body portion 45 of the band 2% adjacent the back rail 13 of the frame 14 obviates jack-knifing of the hands, a common occurrence in the aforementioned prior art sinuous spring hand arrangements.

Since the rear end section 23 of the spring band 20 is bent downwardly at a greater angle than the front end section 29, greater stored resilience is developed in the rear of the body portion 45 of each band 20. Thus support is provided to its greatest extent in that area under the spine of the seated subject where the bulked weight is concentrated. This arrangement further enhances the antibuckcting and, especially, anti-jack-kuifing features of the present invention.

At tie same time, the differential in bend angles of the downwardly bent rear end section 28 and front end section 29 produces a lesser arc in the rear of the body portion 45 of the bend 29 than in the front portion thereof, as illustrated in FIGURE 1. A highly desirable rearwardly sloping contour or profile of the sinuous spring band arrangement 1%) is thus achieved as an added feature of the relative bend angle differential.

The seat afforded by the use of spring assemblies 11 embodying the first form of the present invention hereinbefore described can generally be characterized as a firm seat, as pointed out. The firm scat results from the arcuate movement of the inner linear segments 32 and 36 on opposite ends of the spring bands 20 with relatively high rate of increase in compression in the body portion 45 of the bands as the subject is seated. In contrast to this arrangement, a medium firm seat is afforded by the spring band assemblies 111 illustrated in FIGURE 4, as has also been pointed out. Ths medium firm seat is atforded by providing lesser rate of increase in stored resilience developed in the spring bands 12%) adjacent the front rail 12 of the frame 14 as a subject is seated.

Precedent to describing a spring band 126 in its assembly 111, reference is made to FIGURE 4 and the illustration of the band in relaxed relationship. The relaxed band 129 includes a rear end section 128 bent inwardly of the circle at an angle of approximately 99" thereto, and a front end section 129 bent inwardly of the circle at an angle of approximately 70-80. The rear end section 123 includes the last linear segment 13%) in the band 12s) and the last semi-circular segment 131 thereof, bent inwardly about the second last linear segment 132. The front end section 129, on the other hand, includes the second last linear segment 134 adjacent the opposite end of the band, and the second last semi-circular segment 135 thereof, bent inwardly about the third last linear segment 13s.

in distinction from the spring band 20 hereinbefore described in relation to the spring band assembly 11 embodying features of a first form of the present invention, the spring band 120 includes an extension section 137 bent upwardly from the downwardly extending front end section 129. The extension section 137 includes the last linear segment 13% at the front end of the band 12% and the last semi-circular segment 139 tl ereof, bent upwardly about the second last linear segment 134 at an angle of approximately 100 to the plane of the linear segments 134- and 13;; and their connecting semi-circular segment 135'.

Referring to the spring assembly 111 as illustrated in FIGURE 3, the sinuous band is connected to the front rail 12 by the EK clip 21 and the back rail 13 by the EK clip 22. In this light, the last linear segment of the rear end section 28 is held in the loop 40 of the EK clip 22 while the last linear segment 138 on the ex tension section 137 of the band 21} is retained in the loop 41 of the EK clip 21. Each end of the band 20 is thus mounted for pivotal movement about corresponding end linear segments 130 and 138 held in EK clip loops 40 and 41, respectively.

When the spring band 120 is stretched between the front rail 12 and the back rail 13 in the foregoing manner, a downward torque 0r moment arm is introduced in the band adjacent the back rail 13 by the downwardly bent end section 128 of the band, in identical fashion to the first form of spring assembly 11 hereinbefore discussed. At the same time, the downwardly bent attitude of the front end section 129 of the band 120 introduces a downward torque or moment arm in the band adjacent the front rail 12, albeit through the extension section 137 of the band. These opposing torques develop stored resilience in the central body portion of the band 120.

As the subject lowers into seated relationship on the spring band assemblies 111, the rear end section 128 of the band pivots about its mounting linear segment 130 and tends to further compress or develop stored resilience in the central body portion 145 of the band. At the same time, the actual pivot point of the front end section 129 of the band 120 is displaced from the linear segment 134 to the free end linear segment 138 of the extension section 137. Accordingly, the effective pivot axis of the front end section 129 defined by its linear segment 1'34 moves linearly inward and downward of the spring band 120 in a translatory movement. The stored resilience developed in the body portion 145 of the spring band 120 by the front end section 129 thereof is, accordingly, increased at a substantially lesser rate than is the stored resilience developed by the front end section 29 of the spring band 20 hereinbefore discussed in relation to the first form of the present invention. Accordingly, a slightly softer seat, which on our relative scale is defined as medium firm, is effected by the spring band assembly 111.

Nevertheless, albeit at a lesser rate, stored resilience in the body portion 145 of the spring band 120 is progressively increased, increasing the strength of the spring assembly 111. As a result, bucketing of the band in the central body portion 145 is avoided. Correspondingly, stored resilience developed in the body portion 145 of the band 120 adjacent the back rail 13 obviates jackknifing of the band.

Similarly to the spring band assembly 11 hereinbefore discussed, greater stored resilience forces are developed in the rear of the body portion 145 of each band 120 because of the greater angle of bend of the rear end section 128. Support is once more provided to its greatest extent in the area under the spine of the seated subject where the bulk of weight is concentrated. Anti-bucketing and anti-j-ackknifing features of the present invention are further enhanced.

Once again, the differential in bend angles of the downwardly bent rear end section 128 and front end section 129 produce a lesser arc in the rear of the body portion 145 of the band 128 than in the front portion thereof, as illustrated in FIGURE 3. The highly desirable rearwardly sloping contour or profile of the sinuous spring arrangement 10 is also achieved in this form of the present invention.

In contrast to the seats aiforded by the use of spring assemblies 11 or 111 embodying the first or second forms of the present invention, as hereinbefore described, a medium soft seat is afforded by the spring band assembly 211 illustrated in FIGURE 5, as has also been pointed out. This medium soft seat is the result of providing a lesser rate of increase in stored resilience development in the spring band 220 adjacent the back rail 13 of the frame 14, as a subject is seated.

Precedent to describing the spring band 220 in its assembly 211, reference is made to FIGURE 6 and the illustration of the band in relaxed relationship. The relaxed band 220 includes a rear end section 228 bent inwardly of the circle at an angle of approximately 8090 thereto, and a front end section 229 bent inwardly of the circle at an angle of approximately 70- 80. The rear end section includes the second-last linear segment 230 in the band 220 and the second-last semicircular segment 231 thereof, bent inwardly about the third last linear segment 232. The front end section 229, on the other hand, includes the last linear segment 234 adjacent the opposite end of the band, and the last semicircular segment 235 thereof, bent inwardly about the second last linear segment 236.

In distinction from the spring band 20 and 120 hereinbefore described, however, the spring band 220 includes an extension section 257 bent upwardly from the downwardly extending rear end section 228. The extension section 257 includes the last linear segment 258 at the rear end of the band 220 and the last semi-circular segment 259 thereof, bent upwardly about the second last linear segment 230 at an angle of approximately 110 to the plane of the linear segments 2'30 and 232 and their connecting semi-circular segment 231.

Referring to the spring assembly 211 as illustrated in FIGURE 5, the sinuous band 220 is connected to the front rail 12 by the BK clip 21 and the back rail 13 by the EK clip 22. In this light, the last linear segment in the extension section 257 on the rear end section 228 is held in the loop 40 of the EK clip 22 while the last linear segment 234 on the front end section 229 is retained in the loop 41 of the EK clip 21. Each end of the band 20 is thus mounted for pivotal movement about corresponding ends linear segments 258 and 234 held in EK clip loops 40 and 41, respectively.

When the spring band 220 is stretched between the front rail 12 and the back rail 13 in the foregoing manner, a downward torque or moment arm is introduced in the band adjacent the front rail 13 by the downwardly bent end section 229 of the band, in identical fashion in the first form of spring assembly 11 hereinbefore discussed. At the same time, the downwardly bent attitude of the rear sections 228 of the band 220 introduces a downward torque or moment arm in the band adjacent the back rail '13, albeit through the extension section 257 of the band. These opposing torques develop store resilience in the central body portion 245 to the band 220.

As the subject lowers into relationship on the spring band assembly 211, the front end section 229 of the band pivots about its mounting linear segment 234 and tends to further compress or develop stored resilience in the body portion 245 of the band. At the same time the actual pivot point of the rear end section 228 is displaced from the linear segment 230 to the free end linear segment 258 on the extension section 257. Accordingly, the effective pivot axis of the rear end section 228 defined by its linear segment 230 moves linearly inward and downward of the spring band 220 in a translatory movement.

The stored resilience developed in the body portion 245 of the spring band 220 by the rear end section 228 thereof, is accordingly, increased at a substantially lesser rate than is the stored resilience developed by the rear end sections 28 and 128 of the spring bands 20 and 120 hereinbefore discussed in relation to the first tow forms of the present invention. Since the more acutely bent rear end section 228 of the spring band 220 normally develops slightly greater stored resilience in the band adjacent the rear end thereof than the front end section 229, modification of its capacity for inducing stored resilience produces a relatively softer seat than the spring assembly 111 hereinbefore discussed; a seat which on our relative scale is defined as medium soft.

Regardless, however, bucketing in the band in the central body portion 245 is avoided, as is jack-knifing of the band adjacent the back rail 13. Extensive support is still provided in the area under the spine of the seated subject and a highly desirable rearwardly sloping contour or profile of the sinuous spring arrangement 10 is also achieved in this form of the present invention.

A fourth form of spring band assembly embodying features of the present invention is illustrated generally in FIGURE 7 and, in our relative scale of firmness versus softness, provides a soft seat. This sof seat is afforded by providing a lesser rate of increase in stored resilience developed in spring band 320 adjacent both the front rail 12 and the back rail 13 of the frame 14 as a subject is seated.

The spring band 320 is illustrated in relaxed relationship in FIGURE 8. The band 320 includes a rear end section 228 bent inwardly of the circle at an angle of approximately 80-90 thereto, and a front end section bent inwardly of the circle at an angle of approximately 7080. To this extent it is identical in construction to the spring band hereinbefore discussed.

In distinction from the spring band 29, but similar to the bands 120 and 220 also hereinbefore discussed, the band 329 includes an extension section 337 bent upwardly from the downwardly extending front end section 129 and an extension section 357 bent upwardly from the downwardly extending rear end section 328. Corresponding linear segments 334 and 358 are retained in EK clip loops 41 and 40, respectively, on the front rail 12 and back rail 13.

As the subject lowers into seated relationship on the spring band assemblies 311, the effective pivot axes of the front end section 329 and the rear end section 328 move linearly inward and downward of the spring band 320 in a translatory movement. Total stored resilience in the spring band 320 is developed at a lesser rate than any of the bands 20, 120, 220, hereinbefore discussed, and a still softer seat, which on our relative scale is defined as sof is effected.

Nevertheless, the assets of the basic spring construction embodying the present invention are retained. Bucketing of the band in the central portion 345 is avoided along with jack-knifing of the band adjacent the back rail 13. The greatest amount of support is provided in the area under the spine of the seated subject where the bulk of Weight is concentrated. A lesser arc is developed in the rear of the body portion 345 than in the front portion thereof, as illustrated in FIGURE 7, and a highly desirable rearwardly sloping contour or profile is achieved.

Turning to FIGURES 10-14, several variations on back rail connections between sinuous spring bands and the back frame rail are illustrated. Each provides the back rail translation and vector thrust hereinbefore discussed in relation to the spring assemblies 211 and 311, for example.

In FIGURE 10, a variation on the first form of furniture spring arrangement illustrated in FIGURE 9 is shown generally at 410. The spring arrangement 410 includes a sinuous spring band assembly 411 mounted between the front rail (not shown) and the back rail 413 of a frame 414. The sinuous spring band assembly 411 includes a sinuous spring band 420, identical to that herebefore discussed, connected to the back rail 413 through a back connector sub-assembly 422 which provides enhanced lateral stability to the spring band 420 according to the present variation, in addition to providing the elicited advantages of the present invention.

The back connector sub-assembly 422 comprises a. diverging pair of helical springs 4220 which interconnect the sinuous spring band 420 with the back rail 413. As will be noted, it includes a I clip 423 which encircles the end linear segment in the depending lever arm 424 of the spring band 420 and has three apertures formed therein, the outer two bracketing the inner one. The apertures receive the book ends of the helical springs 422a in the manner illustrated. In a corresponding manner, the opposite hook ends of the helical springs 422a extend through apertures in L-clips 432 secured to the back rail 413.

It should be recognized that the clip 423 and helicals 422a serve as translatory members to permit the back end of the band 420 to move down while torque is induced in it through the arm 424. As such, a substantially soft seat, on our relative scale, is developed. In addition, the use of helical springs to connect the band 420 to the back rail 413 provides the additional feature of automatic adjustability of the spring assembly 410 to fit a seated persons thigh length. The best flexing of the arm 424 for the specific comfort of that weight and size sitter is achieved.

FIGURE 11 illustrates yet another variation on the first form of furniture spring arrangement, as shown at 510. The furniture spring arrangement 510 includes a sinuous spring band assembly 511 mounted between the front rail (not shown) and the back rails 513 of a seating frame 514. The assembly 511 includes a sinuous spring band 520 identical to that hereinbefore discussed with the exception that a Z-hook 521 is provided extending directly outwardly from the last linear segment 530. The Z-hook 521 is then connected to the back rail 513 through a back connector sub-assembly 522.

When the spring band assembly 511 is stretched between the front rail (not shown) and the back rail 513, a downward torque or moment arm is introduced in the sinuous spring band 520 adjacent the back rail 513 by virtue of the downwardly bent rear end section 528 of the spring band. At the same time, by virtue of the horizontally extending band section 529, Z-hook 521, and helical, the rear end of the band 520 is permitted to translate downwardly. Again, a relatively soft seat is assured by this translation and vector thrust. The automatic adjustability hereinbefore referred to is also this construction.

FIGURE 14 illustrates, at 510a, a slight modification of the furniture spring arrangement variation 510 seen in FIGURE 11. In the modification 510a, note that the Z-hook 521a actually replaces the horizontally extending band section 529 entirely. In this modification, it is the extending Z-hook 521a, in combination with the helical 522a, which permits downward translation of the spring band end to assure a soft seat.

A variation on the second form of the present invention is illustrated at 610 in FIGURE 12. In this case, a back connector sub-assembly 622 is provided which connects the last linear segment 651 of the spring band 620 to the back rail 613 in articulated relationship. As will be seen, the back connector sub-assembly includes a U-shaped wire clip 623 which has a pair of loops 624 formed on its free ends for encircling the last linear segment 651. The base 625 of the U-shaped link 623 is retained in a standard EK clip 630. This construction provides translation downwardly at the rear rail of the furniture frame, of course, achieving vector thrust and a relatively soft seat, albeit not as soft as when a helical is used.

FIGURE 13 illustrates another variation of the second form of the present invention, as illustrated generally at 710. In this case, the rear end 720:: of the sinuous spring band 720 has its third and second last semi-circular segments 721 and 722 bent downwardly in a plane about the fourth last linear segment 723. The last semicircular segment 724 is bent upwardly about the second last linear segment 725 and the last linear segment is secured to the frame 713 by an EK clip 726 or the like. The action at the rear end 720a is similar to the action of the spring arrangement 211 illustrated in FIGURE 5.

Turning now to FIGURE 15 of the drawings, a spring arrangement embodying features of this invention is disclosed in its simplest form at 810. The spring arrangement 810 comprises a spring band 820 arranged and connected between a front rail 812 and a back rail 813 according to the invention.

The band 820 is connected at its frontmost linear segment 830 by a conventional EK clip. As such, the front end 820a of the band 820 is free to pivot downwardly about its point of attachment with the front rail 812.

Adjacent the back rail 813, the band 820 is bent downwardly into a torque arm 831 about the third last linear segment 832 of the band. A horizontally extending translation arm 833 defined by the last two linear segments 835 and 836 and their enclosed semi-circular segment extends to and is pivotally retained by a standard EK clip 840.

The back end 82% construction of the spring band 820 provides the vector-thrust translatory movement of the band beneath the seat of the person being seated. Torque is slowly and evenly induced in the band 820 as it sinks at its rear end 820a, providing a luxuriously soft, yet firm seat with up-thrust under the occupant as he rises.

While several embodiments described herein are at present considered to be preferred, it is understood that various modifications and improvements may be made therein, and it is intended to cover in the appended claims all such modifications and improvements as fall Within the true spirit and scope of the invention.

What is desired to be claimed and secured by Letters Patent of the United States is:

1. In a spring arrangement for furniture or the like, having a front rail and a back rail, the improvement in spring band assembly comprising: a sinuous spring band which in its relaxed form is substantially circular in profile and which in its installed operational form is stretched between the rails, said band including a series of semicircular segments interconnecting a series of linear segments, a linear segment at the front free end of said band being connected to the front rail for pivotal movement relative thereto, a back portion of said band bent downwardly from the main body portion of said band and defining an interior angle of at least to degrees with said main body portion when said band is in its installed, operational form, the profile of said main body portion defining a flattened curve without bends extending out of the curve from adjacent said front end of said band to said back portion, substantially horizontal means extending generally parallel to said main body portion from the lower end of said back portion, the free end of said substantially horizontal means being connected to the back rail for pivotal movement relative thereto, said downwardly bent portion simultaneously translating downwardly and rotating outwardly to compress said main body portion of said band as load is applied to the spring assembly.

2. The improvement in spring assembly of claim 1 further characterized in that said downwardly bent back portion comprises only a single semi-circular segment and its bracketing linear segments.

3. The improvement in spring band assembly of claim 2 further characterized in that said substantially hori zontal means comprises a band portion including a single semi-circular segment and its bracketing linear segments.

4. The improvement in spring band assembly of claim 2 further characterized by and including helical spring means connecting said downwardly bent back portion of said spring band to the back rail.

5. The improvement in spring band assembly of claim 1 further characterized in that said substantially horizontal means includes clip means pivotally connected to the last linear segment on said spring band adjacent said back rail, said clip means being connected to the back rail for pivotal movement relative thereto.

6. The improvement in spring band assembly of claim 5 further characterized by and including helical spring means connecting said clip means to the back rail.

7. The improvement in spring band assembly of claim 1 further characterized in that said substantially horizontal means includes an outwardly extending J-hook on said downwardly bent back portion of said band, and helical spring means connecting said J-hook to the back rail for pivotal movement relative thereto.

8. The improvement in spring band assembly of claim 1 further characterized by and including a front portion 12 of said band bent from the main body portion of said band at a predetermined angle.

References Cited UNITED STATES PATENTS 2,646,108 7/1953 Norman 2671 3,156,457 11/1964 Hampson 267-1 3,207,499 9/1965 Vogel 2671 12 m ARTHUR L. LA POINT, Primary Examiner. 

